Treatment of pain is of great importance in medicine. Analgesic agents as a rule act by blocking opioid receptors. Conventional opioids, such as morphine, are thus opioid analgesics which are often employed in clinical pain therapy because of their potent analgesic action. These selectively activate the μ receptor. However, undesirable side effects of such pain therapy are sometimes considerable centrally mediated side effects, such as respiratory depression, vomiting and bradycardia. Possible psycho-dependencies are furthermore a disadvantage.
In view of the large number of types of pain and diseases associated with pain, there is a great need for active analgesics.